Helianthus plant named ‘Double Whammy’

ABSTRACT

A new cultivar of  Helianthus , ‘Double Whammy’, that is characterized by its upright and compact plant habit, its large inflorescences that are golden yellow in color, and its double inflorescences with a row of ray florets on the outer edge and disc florets with expanded petals (ray floret-like) that are uniformly formed throughout bloom.

Botanical classification: Helianthus decapetalus×multiflorus.

Variety denomination: ‘Double Whammy’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Helianthus decapetalus×multiflorus and will be referred to hereafter by its cultivar name, ‘Double Whammy’. ‘Double Whammy’ represents a new Helianthus, an herbaceous perennial grown for landscape use.

The Inventor discovered the new Helianthus as a naturally occurring whole plant mutation in 2009 in a nursery bed in Pukekohe, New Zealand. The parentage is unknown, however based on its characteristics, the new cultivar is an interspecific hybrid between Helianthus decapetalus and Helianthus multiflorus.

Asexual propagation of the new cultivar was first accomplished by division by the Inventor in Mansell Gamage, Hereford, United Kingdom in spring of 2011. Asexual propagation by division and stem cuttings has shown that the characteristics of the new cultivar are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent the characteristics of the new cultivar. These attributes in combination distinguish ‘Double Whammy’ as a unique cultivar of Helianthus.

-   -   1. ‘Double Whammy’ exhibits an upright and compact plant habit.     -   2. ‘Double Whammy’ exhibits large inflorescences that are golden         yellow in color.     -   3. ‘Double Whammy’ exhibits double inflorescences with a row of         ray florets on the outer edge and disc florets with expanded         petals (ray florets like) that are uniformly formed throughout         bloom.         Typical plants of Helianthus decapetalus, a probable parent         plant, differ from ‘Double Whammy’ in having single flowers with         typical disc florets, in having leaves that are elliptic in         shape with a more pronounced acuminate apex and greater         pubescence, and in having a more spreading plant habit. Typical         plants of Helianthus multiflorus, a probable parent plant,         differ from ‘Double Whammy’ in having double inflorescences that         lack a distinct row of outer rays florets (Dahlia like) and in         having longer stems and wider leaves. ‘Double Whammy’ can be         most closely compared to the cultivars ‘Sunshine Daydream’ (not         patented) and ‘Loddon Gold’ (not patented). ‘Sunshine Daydream’         is similar to ‘Double Whammy’ in having double inflorescences         that are similar in color. ‘Sunshine Daydream’ differs from         ‘Double Whammy’ in having inflorescences that lack a distinct         row of ray florets and are more dome-shaped. ‘Loddon Gold’ is         similar to ‘Double Whammy’ in having double inflorescences.         ‘Loddon Gold’ differs from ‘Double Whammy’ in having         inflorescences that are more yellow in color with less distinct         ray florets, in blooming later in the season, and in having a         taller plant height.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying colored photographs illustrate the overall appearance and distinct characteristics of the new Helianthus. The plants in the accompanying photographs were taken of a plant about two years in age as grown in a garden in Mansell Gamage, Hereford, United Kingdom.

The photograph in FIG. 1 depicts a plant of ‘Double Whammy’ in bloom.

The photograph in FIG. 2 shows a close-up of the inflorescences of ‘Double Whammy’.

The inflorescences are golden yellow in color and the reddish tinge in the photographs is due to shading of the dense florets. The colors in the photographs may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new Helianthus.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of the new cultivar with the data taken from plants 10 months in age (from a rooted liner) as grown in two-gallon containers in Watsonville, Calif. The phenotype of the new cultivar may vary with variations in environmental, climatic, and cultural conditions, as it has not been tested under all possible environmental conditions. The color determination is in accordance with The 2007 R.H.S. Colour Chart of The Royal Horticultural Society, London, England, except where general color terms of ordinary dictionary significance are used.

-   General description:     -   -   Blooming period.—4 to 6 weeks in late July to late August             and can extend into September in the United Kingdom.         -   Plant type.—Herbaceous perennial.         -   Plant habit.—Upright and compact.         -   Height and spread.—Reaches about 1.2 m in height and about             76 cm in spread in the landscape.         -   Hardiness.—At least in U.S.D.A. Zone 5B.         -   Diseases and pests.—No susceptibility or resistance to             diseases or pests has been observed.         -   Root description.—Fibrous.         -   Propagation.—Stem cuttings preferred.         -   Growth rate.—Moderate to vigorous. -   Stem description:     -   -   Shape.—Slightly oval.         -   Stem color.—Main stem; a blend of 144A and 144B; lateral             stems; 144B.         -   Stem size.—Main stem; an average of 38 cm in length and 7 mm             in diameter, lateral branches; an average of 15 cm in length             and 2 mm in width.         -   Stem surface.—Main stem; slightly pubescent with fine             ridges, lateral stems; slightly pubescent.         -   Stem number and branching.—An average of 7 main stems with             an average of 7 lateral stems per main stem.         -   Internode length.—An average of 2 cm. -   Foliage description:     -   -   Leaf shape.—Ovate.         -   Leaf division.—Simple.         -   Leaf base.—Truncate and slightly rounded.         -   Leaf apex.—Acuminate.         -   Leaf venation.—Pinnate, 145A on upper surface and lower             surface.         -   Leaf margins.—Serrate.         -   Leaf attachment.—Petiolate.         -   Leaf arrangement.—Alternate.         -   Leaf size.—Matures to an average of 10 cm in length and 7.5             cm in width.         -   Leaf color.—Young leaves; upper surface 137A, lower surface             138A, mature leaves; upper surface N189A, lower surface             147A.         -   Leaf surface.—Both surfaces dull and sparsely pubescent.         -   Stipules.—None. -   Flower description:     -   -   Type.—Capitulum, double with a row of ray florets around the             margin and showy disc florets in the center (expanded             petals), relatively flat in aspect.         -   Capitulum number.—An average of 12 capitulums per stem             emerging from nodes from the apex to the base with new             blooms opening throughout the bloom period.         -   Lastingness of inflorescence.—About 10 days.         -   Capitulum size.—About 8 cm in depth and 2.5 cm in diameter,             disc size is about 2 cm in depth and 4.8 cm in diameter.         -   Fragrance.—None detected.         -   Involucral bracts or phyllary.—About 36 arranged in 3             overlapping rows, up to 1.2 cm in length and 3 mm in width,             fused at base, acuminate apex, lanceolate in shape, 137A in             color, entire ciliate margin and slightly puberulent on both             surfaces, held slightly reflexed.         -   Buds.—Globose in shape, average of 2 cm in diameter and             height, color; phyllary are 137A, ray florets are 7A, disc             floret portion 145A.         -   Peduncle.—Strong, held upright to a 30° angle from stem (0°             vertical), an average of 15 cm in length and an average of 2             mm in diameter, 144C in color, pubescent surface.         -   Ray florets (sterile).—Average of 20, elliptical in shape,             vertical ridges on both surfaces, about 1.6 cm in length and             1.2 cm in width, acute apex, broadly cuneate base, entire             margin, glabrous on upper and lower surface, initially held             slightly upright and become horizontal, then slightly             downward as they mature, color of upper and lower surface             when opening and fully open; 9A, color of upper and lower             surface when drying; 15A.         -   Disc florets (bisexual and sterile).—Numerous, about 400,             tubular in shape, arranged spirally on a disk receptacle to             form a cushion shaped mound, florets are about 2.5 mm in             length and 5 mm in width, petals (5) are fused into tube             about 1.5 cm in length and 5 mm in width and 7A in color on             both surfaces, most have single expanded petals and are             sterile (ray floret-like) and are an average of 2.8 cm in             length and 7 mm in width with same characteristics as ray             florets, campanulate calyx (fused sepals), about 1.5 mm in             width and length, glabrous on outer and inner surface, and             1C in color. -   Reproductive organs (fertile disc florets only):     -   -   Gynoecium.—Pistil; 1, 1 cm in length, style; 9 mm in length,             1C in color, surrounded by stamens at base, stigma; bifid,             each arm is curled, about 1 mm in length and 7A in color,             ovary; inferior, oblong in shape, 4 mm in length and 1.5 mm             in width, glabrous surface, NN155C in color.         -   Androcoecium.—Stamens; 5, fused, form a cylinder around base             of style, about 5 mm in length and 0.3 mm in width,             filaments are minute and 7B in color, stamens are 200D in             color, pollen is low in quantity and 11A in color.         -   Seed.—Fertile seed development has not been observed. 

It is claimed:
 1. A new and distinct cultivar of Helianthus plant named ‘Double Whammy’ substantially as herein illustrated and described. 